Bare words / new keywords in Python

Question

I wanted to see if it was possible to define new keywords or, as they're called in WAT's Destroy All Software talk when discussing Ruby, bare words, in Python.

I came up with an answer that I couldn't find elsewhere, so I decided to share it Q&A style on StackOverflow.

Answer 1

I've only tried this in the REPL, outside any block, so far. It may be possible to make it work elsewhere, too.

I put this in my python startup file:

def bareWordHandler(type_, value, traceback_):     if isinstance(value, SyntaxError):         import traceback          # You can probably modify this next line so that it'll work within blocks, as well as outside them:         bareWords = traceback.format_exception(type_, value, traceback_)[1].split()          # At this point we have the raw string that was entered.         # Use whatever logic you want on it to decide what to do.         if bareWords[0] == 'Awesome':             print(' '.join(bareWords[1:]).upper() + '!')             return     bareWordsHandler.originalExceptHookFunction(type_, value, traceback_)  import sys bareWordsHandler.originalExceptHookFunction = sys.excepthook sys.excepthook = bareWordsHandler 

Quick REPL session demonstration afterwords:

>>> Awesome bare words BARE WORDS! 

Use responsibly.

Edit: Here's a more useful example. I added in a run keyword.

if bareWords[0] == 'from' and bareWords[2] == 'run':         atPrompt.autoRun = ['from ' + bareWords[1] + ' import ' + bareWords[3].split('(')[0],                             ' '.join(bareWords[3:])]         return 

atPrompt.autoRun is a list of variables that, when my prompt is displayed, will automatically be checked and fed back. So, for example, I can do this:

>>> from loadBalanceTester run loadBalancerTest(runJar = False) 

And this gets interpreted as:

from loadBalancerTest import loadBalancerTest loadBalancerTest(runJar = False) 

It's kind of like a macro - it's common for me to want to do this kind of thing, so I decided to add in a keyword that lets me do it in fewer keystrokes.